Move HashMetricName to base namespace.

base/metrics/BUILD.gn

 # Copyright (c) 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 source_set("metrics") {
   sources = [
     "bucket_ranges.cc",
     "bucket_ranges.h",
     "field_trial.cc",
     "field_trial.h",
     "histogram.cc",
     "histogram.h",
     "histogram_base.cc",
     "histogram_base.h",
     "histogram_delta_serialization.cc",
     "histogram_delta_serialization.h",
     "histogram_flattener.h",
     "histogram_macros.h",
     "histogram_samples.cc",
     "histogram_samples.h",
     "histogram_snapshot_manager.cc",
     "histogram_snapshot_manager.h",
+    "metrics_hashes.cc",
+    "metrics_hashes.h",
     "sample_map.cc",
     "sample_map.h",
     "sample_vector.cc",
     "sample_vector.h",
     "sparse_histogram.cc",
     "sparse_histogram.h",
     "statistics_recorder.cc",
     "statistics_recorder.h",
     "user_metrics.cc",
     "user_metrics.h",
     "user_metrics_action.h",
   ]
 
   configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/debug",
     "//base/json",
     "//base/memory",
   ]
 
   allow_circular_includes_from = [ "//base/memory" ]
 
   visibility = [ "//base/*" ]
 }
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "metrics_hashes_unittest.cc",

[Alexei Svitkine (slow), 2015/11/25 21:05:40]

The other unit tests in this folder are listed here:

https://code.google.com/p/chromium/codesearch#chromium/src/base/BUILD.gn&l=1372

Probably makes sense to keep them consistent and put it there too.

[bcwhite, 2015/11/25 22:58:26]

Ahh, there they are.  Will do.

+  ]
+
+  deps = [
+    ":metrics",
+    "//base:prefs_test_support",
+    "//base/test:test_support",
+    "//components/variations",
+    "//testing/gtest",
+  ]
+}